Watersheds Box

This box covers watersheds, wetlands, and the shaping of the San Francisco Bay Area. Students will create several 3 dimensional classroom models to explore watersheds, erosion, sedimentation, and wetlands.Students ...

This box covers watersheds, wetlands, and the shaping of the San Francisco Bay Area. Students will create several 3 dimensional classroom models to explore watersheds, erosion, sedimentation, and wetlands.Students will explore the geography of the local area through maps and physical exploration, thereby learning where water in the Bay comes from and the path it takes before it reaches the ocean. Throughout the unit are strategies to apply classroom learning to the real world in the form of:

projects - studying erosion at a local creek and staging a town hall meeting about California's levee system

field trips - to the San Francisco Bay model and a canoe/restoration trip with Save the Bay

1. Water Cycle Stories

In this lesson, students review the water cycle (a concept most have hopefully explored before in elementary school science) and write stories to describe the journey of a water molecule ...

Summary In this lesson, students review the water cycle (a concept most have hopefully explored before in elementary school science) and write stories to describe the journey of a water molecule through the water cycle. They begin by labeling a drawing of the water cycle, noting the locations that water may be stored on the planet and the processes through which water travels from one location to another. They then envision several journeys as a class before writing a story to describe the journey of a water molecule through the water cycle. An optional mini-investigation to complement this lesson involves observing the transition of water through its 3 phases (ice, water, water vapor) after an ice cube is zipped into a resealable plastic bag and taped to a sunny window.

Objectives Can list the 3 phases of water and understand how heat contributes to the transition from one phase to another. Can discuss the various locations where water is stored on Earth and the processes through which water travels from one location to another. Can describe the water cycle.

1. Water Cycle Stories - Logistics

Time 1-2 hours depending on the students’ previous exposure to the phases of matter and the water cycle

Grouping individual

Materials For water cycle discussion:

Glass of ice water to start the discussion

Copies of Water Cycle Stories handout

Overhead projector (or draw a copy of the image on the board)

Overhead transparency of Water Cycle diagram

Dice

For optional mini-investigation each student needs:

Ziplock bag

1 ice cube

1 sample cup (the little paper cups ketchup is sometimes served in)

several scales or balances for students to weigh their bag

tape

sunny window or sunny exterior wall

Setting Classroom

Magic School Bus: at the Waterworks

While I was reading The Magic School Bus,they went inside a cloud. Because this is not a field trip, there should be no driving into clouds :). But in Inside a Hurricane, They make a water cycle experiment.

Materials: Oven mitten,Kettle,Ice,Strainer,Water

Experiment:

Put water in kettle.

Turn on the stove.

As the steam comes up, put ice in strainer.

Open top of kettle.

Watch as the water moves around.

1. Water Cycle Stories - Background

Teacher Background The water cycle is at the center of many scientific topics, from watersheds (like this unit) to weather patterns to ice ages. The main idea is that almost all the water that exists on Earth today was there since the planet formed 4.6 billion years ago. However, water molecules do not stay in one place for long, at least not on a geologic time scale. The sun drives a continual process of evaporation, condensation, freezing, and melting that allows any given water molecule to travel from location to location on Earth. Thus the water cycle is the journey that water takes through its various phases (or states) – solid ice, liquid water, and gaseous water vapor – as it travels through Earth’s systems.

Water can exist in 4 phases or states – solid, liquid, gas and plasma – although plasma has little relevance to most everyday events including the water cycle. The molecules of a solid are tightly packed and bonded together so that the substance retains its shape. The molecules of a liquid are closely packed but can move relative to each other so that the substance flows. The molecules of a gas are independent of each other and move about freely in 3 dimensions. The transition from one phase to another is governed by temperature and pressure. As temperature increases and pressure decreases, a solid substance will generally transition to a liquid (it melts) and then from a liquid to a gas (it evaporates). As temperature decreases and pressure increases, a gas will generally transition to a liquid (it condenses) and then from a liquid to a solid (it freezes). It is possible for substances to transition straight from a solid to a gas in a process called sublimation. For instance, snow sometimes sublimates without turning to liquid water first. Similarly, dry ice sublimates straight to carbon dioxide gas.

With respect to the water cycle, water as a gas may travel huge distances across oceans and continents before it condenses and turns to rain or snow. Water as a liquid will flow across the Earth’s surface and percolate into the ground. Thus, water travels a lot as it undergoes phase changes. Most of this is governed by temperature as the result of the sun’s energy and less by pressure. One can therefore think of the water cycle as powered by the sun.

The water cycle is illustrated below. There are 6 major storage locations for water:

Precipitation (rain, snow, sleet, hail, and ice) – Water stored as precipitation in the form of snow is critical to the state of California since most Californians depend on snowmelt to provide them with fresh water throughout the dry summer months.

Glaciers – These giant, slowly moving ice sheets form from snow that compacts and recrystalizes over time to form large ice crystals. Glaciers are more important than many realize. Approximately 75% of the Earth’s fresh water is stored as glaciers, primarily around the polar ice caps.

Groundwater

Living organisms – Our bodies are 50-70% water!

From each of these storage locations, water has ways to travel to other locations. Water may:

Evaporate –from surface water into the atmosphere

Condense – from the atmosphere into precipitation

Melt – from precipitation as snow to surface water or from glaciers to surface water

Freeze – from precipitation as snow to glaciers

Percolate – from surface water to groundwater and back again

Transpire – from living organisms to the atmosphere

Drink – from surface water (or sometimes groundwater) to living organisms

Excrete – from living organisms to surface or groundwater

Student Prerequisites Previous exposure to the phases of matter and the water cycle is helpful but not necessary. If students have not learned about these topics in the past, then on day 1, do the phases of matter mini-investigation and discuss the locations where water is stored. On day 2, analyze the results of the mini-investigation and discuss the transitions between locations in the water cycle.

1. Water Cycle Stories - Getting Ready

Getting Ready For water cycle discussion:

Make copies of the Water Cycle Stories handout for each student.

Make overhead copy of the Water Cycle diagram.

Fill a clear glass with ice water and leave it on a coaster at the front of the room.

1. Water Cycle Stories - Lesson Plan

Lesson Plan Optional mini-exploration:

Ask students what they predict will happen if I zip an ice cube in a Ziplock bag. In particular, what will happen to the weight of the bag as the ice turns to water and then turns to water vapor? Many students will think that the bag will weigh less after the water melts and some of it turns to water vapor.

Have students write down their predictions on a lab notebook. I had my students draw a series of pictures with captions showing the plastic bag now, in 2 hours, and tomorrow.

Try the experiment. Pass out bags, sample cups and ice cubes. Place the ice cube in the sample cup and then place the whole thing in the Ziplock bag. Make sure there is a good quantity of air in the bags before sealing them so that any condensation that accumulates may be observed. Make sure the bags are tightly sealed.

Have each student measure the mass of their bag and record that measurement in their lab notebook before taping the bag to the window or wall. Make sure the sample cup is right-side-up with the ice inside. If you wish, you can use any remaining class time to introduce the locations on Earth where water is stored (Step #10 of the Water Cycle discussion lesson plan below).

The following day, make some observations of the bags before taking them down. The ice should have melted and some condensation will have appeared on the sides of the bag and run down the sides of the bag to collect below the cup.

Take the bags down and remove any tape. Measure the mass of the bags and compare the measurement to the previous day.

Ask the students: Did anything surprise you? Did everything happen according to your predictions? Flow directly into the Water Cycle discussion below.

Water Cycle discussion and storytelling:

Begin by setting the glass of ice water on the table at the front of the room. Ask the students to make observations of the glass. What is happening to the ice? What is happening on the outside of the glass? Why are these things happening?

Allow these initial observations to transition into a discussion of phase change. Ask students what they know about how and why water can transition from ice to liquid water to water vapor. Students may or may not know about how increasing temperature translates into molecular movement – that solids are solids because the molecules are locked in place and can only vibrate while in gases the molecules are energetic and move freely.

Invite 9 volunteers to come to the front of the room. Each student represents one molecule of water. Have them stand closely together in 3 rows of 3 students and interlock arms. They now represent water in its solid form – ice. Tell them that they are cold. They may shiver and vibrate a little but should remain bound together.

Now tell them you have placed the glass of water in a sunny window and the molecules of water in the ice cube have begun to get energized. They can now move around but should stay together in a cluster. They have melted and become liquid water. They should naturally unlink their arms and perhaps might join hands. Allow them to “flow” around the room and use that to illustrate the fluid motion of liquids. If you wish, you can introduce the idea of hydrogen bonding and surface tension as the reasons that liquids stay together.

Now tell them that the sun has become really warm and they are very very excited and can move about freely. The cluster of 9 will soon disperse about the room, probably colliding with desks, other students and the walls of the room. You may need to have the water molecules “freeze” temporarily in order for your explanation to be heard by the students. They have evaporated and now represent water as a gas – water vapor or steam.

Finally, tell them that the sun has set and it is beginning to become cold. When they collide with another water molecule, they should “stick together for warmth”. Soon all the water molecules will form a liquid again. They have now condensed back onto a liquid. You may take things all the way back to the beginning again and tell the molecules to freeze solid by linking arms once again.

Thank your water molecules and have them return to their seats. Review the process of phase change that they observed, noting the way that temperature changed the behavior of the molecules.

Ask the students where the energy that caused the temperature change came from. (The sun.)

Point out that this process – the phase changes of water powered by the sun – is what drives weather patterns, the movement of water around the globe, and the resulting erosion that shapes our landscape. Also point out that while water changes state and moves around, it is rarely created or destroyed. The water that exists on the planet today is OLD. At one time, the water molecules they drank this morning were once in the oceans when the Earth first formed and perhaps even were drunk by a dinosaur and later peed out again. If you did the mini-investigation, draw an analogy between the mini-investigation and the water cycle. The quantity of water in the bag stayed the same just like the quantity of water on the planet has stayed the same since the planet was formed. Just like in the bags, the water on the planet continually changes state and moves around from place to place.

Give students the handout and turn on the overhead projector with the water cycle drawing.

Invite students to name places on or around the planet where water can be found in any of its forms. As students provide one of the 6 major locations where water is stored (surface water, atmosphere, precipitation, glaciers, groundwater, living organisms) fill in that area on the water cycle transparency and have students copy our labels onto their own diagrams. Discuss the importance of each of the storage areas as you label it (see Teacher Background).

Next, ask students how they think water moves from place to place. As they point out each part of the water cycle (evaporate, condense, melt, freeze, percolate, transpire, drink, excrete) introduce an arrow and a label for the diagram.

Once the diagrams are completed, read or tell the students a story of a water molecule that makes a journey through the water cycle. An example of a story that follows a drop of water may be found on the USGS site. There is also a Magic School Bus episode by Pat Relf where Ms. Frizzle’s famous class takes a journey through the water cycle.

Tell the students that they now have the job of telling the story of a water molecule that makes its own journey through the water cycle. Notice that each of the locations where water is stored has a number. Students will roll a dice to figure out where each water molecule will begin and end its journey. On its way, the water molecule must travel through at least 4 different locations including a living organism.

Allow students time to outline their stories during class and check that each student has a reasonable story outline. The story itself can be completed as homework.

1. Water Cycle Stories - Assessments

Assessment

Completed stories can be graded for comprehension.

If you choose to have students share their stories, have students imagine 2 more steps of the water molecule’s journey.

If you did the mini-investigation, have students diagram the water molecules at different stages of the experiment.

Going Further

Using the stories that students write as a rough draft, help students edit and revise their story and turn the stories into illustrated children’s books. These books can be shared with elementary school students.

1. Water Cycle Stories - Sources and Standards

Sources
The mini-investigation was inspired by the Mini Water Cycle lesson in Water Precious Water by the AIMS Education Foundation.

Using students to model the behavior of molecules in a solid, liquid and gas was inspired by a lesson I observed by Michael Geluardi, a science teacher and friend at Piedmont High School in Oakland, CA.

A great resource for additional information about the water cycle may be found on the USGS website.

Standards
Grade 6
Shaping Earth’s Surface
Energy in the Earth System
4. Many phenomena on Earth’s surface are affected by the transfer of energy through radiation and convection currents. As a basis for understanding this concept:
a. Students know the sun is the major source of energy for phenomena on Earth’s surface; it powers winds, ocean currents, and the water cycle.
d. Students know convection currents distribute heat in the atmosphere and oceans.
e. Students know differences in pressure, heat, air movement, and humidity result in changes of weather.

Grade 8
Structure of Matter
3. Each of the more than 100 elements of matter has distinct properties and a distinct atomic structure. All forms of matter are composed of one or more of the elements. As a basis for understanding this concept:
e. Students know that in solids the atoms are closely locked in position and can only vibrate; in liquids the atoms and molecules are more loosely connected and can collide with and move past one another; and in gases the atoms and molecules are free to move independently, colliding frequently.

Reactions
5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept:
d. Students know physical processes include freezing and boiling, in which a material changes form with no chemical reaction.

Chemistry of Living Systems (Life Sciences)
6. Principles of chemistry underlie the functioning of biological systems. As a basis for understanding this concept:
c. Students know that living organisms have many different kinds of molecules, including small ones, such as water and salt, and very large ones, such as carbohydrates, fats, proteins, and DNA.

2. Watersheds and Wetlands

Wetlands book First page of a 6th grade student&#39;s book on wetlands, written and shared with the 4th grade class. Cardstock paper, water spray bottles, markers and sponges are turned ...

SummaryWetlands book: First page of a 6th grade student's book on wetlands, written and shared with the 4th grade class. Cardstock paper, water spray bottles, markers and sponges are turned into models of wetlands and watersheds in this simple activity. Students follow the path of the water (and urban runoff) to a bay and develop an initial understanding of what watersheds are. Then some students add sponges to the borders of their bay to simulate wetlands and compare watersheds with wetlands to those without. Students extrapolate the role of watersheds as reservoirs in times of drought, as sponges in times of flood, and as filters for pollution. Finally, students compare watersheds with wetlands to those without after a “toxic chemical spill” (Koolaid drink mix) to see the effects of pollution throughout the watershed as well as to discover the role of wetlands in reducing the harm of severe pollutants to a bay. This series of activities is an excellent prelude for a wetlands restoration field trip (see the Save the Bay field trip planning guide) so that after learning what wetlands are, they can explore and restore a wetland area firsthand. Another extension and application of these ideas might be an exploration of the students’ own watershed, the effects of urban runoff and watershed protection.

Objectives Can define wetlands and watersheds. Can look at a 3-dimensional model and identify different watersheds. Can explain how runoff carries water, sediments (from natural areas), and pollution (from urban areas) to rivers, bays and oceans. Can understand that an event in a watershed affects all downstream areas. Can describe some of the many important roles wetlands serve in an ecosystem.

2. Watersheds and Wetlands - Logistics

Time 70-90 minutes - approximately 20-30 minutes per wetland for construction, the activity, discussion and clean up. I recommend doing the first activity to introduce the idea of a watershed on one day then do both wetland activities on the following day. If you are short on time or if students are already familiar with the concept of a watershed, then you can add wetlands right away.

1 kitchen sponge cut into 4 rectangular pieces (the yellow sponges with the green scrubbing material are cool because kids can observe a color change in the yellow “soil” portion of the sponge while the green material simulates plants living in the wetlands)

1 water spray bottle (available at most hardware stores near the cleaning supplies or at plant nurseries for watering and misting plants)

a multi-color assortment of water-based markers

The teacher needs:

a stack of white cardstock paper (each team will use 3 sheets)

1 packet of colored drink mix like Koolaid or Hawaiian Punch

1 spoon

optional - map or satellite image of the school and neighboring areas showing the watershed

Everyone needs:

a copy of the Watershed and Wetlands Questions

a sink to clean sponges and dump dirty water

a trash can

Setting classroom

2. Watersheds and Wetlands - Background

Teacher Background The concept of the watershed forms the foundation of much environmental science. Formally, a “watershed” is the area of land that water flows over and through on its way to a larger body of water like a creek, river, lake, or bay. Practically, this means that a watershed is all the land that drains into a specific body of water. Every house, school, and neighborhood is part of a watershed. Studying ones own watershed allows students to apply scientific knowledge to their neighborhood and community and are easy ways for students to make connections between their actions (pollution, water conservation, habitat restoration, etc.) and the quality of the environment they live in.

Watersheds may be as large as several states (the Mississippi River watershed for example) or as small as a few city blocks. For instance, the San Francisco Bay watershed covers the entire western slope of the Sierra Nevada Mountains, the Central Valley of California, the Sacramento River Delta, and the many smaller creek systems that surround the San Francisco Bay itself. This area of land is approximately 40% of the entire state of California! One could also refer to the Codornices Creek watershed in Berkeley that my school is near. It’s area encompasses a narrow strip of land 5 blocks wide and 3 miles long between the San Francisco Bay and the Berkeley hills. Both are equally valid watersheds to discuss since students can see their personal connection both to the Bay and to the neighborhood they live and go to school in.

A watershed begins in the tallest mountain areas where water falls as rain or snow. This water then trickles into rivulets, rivulets merge into creeks, and creeks merge into rivers on the water’s way downhill. Eventually, these streams of water reach the larger body of water under study – a bay, a river, a lake, a creek. Much of this water will also seep into the ground as groundwater and may travel much more slowly through the soil and rock and perhaps underground aquifers to reach a body of water. Any land a water drop has traveled over or through to get to the body of water being studied belongs to that watershed. All this movement of water is part of the larger water cycle (see the Water Cycle Stories Lesson).

I found that my students had a difficult time understanding that a watershed meant land and did not just include the creeks, rivers, lakes and bays. Pointing out that a watershed is usually bordered by ridges helps. Using a 3-D map to illustrate separate valleys that have separate watersheds also helps.

At the edges of a watershed, particularly those with little human development, one will find wetlands. Broadly defined, “wetlands” are transitional areas between land and water habitats. More specifically, the wetlands are characterized by:

lots of water - the water table is at the surface or close to it most of the time

soil that is wet much of the time (although some wetlands are actually dry for more of the year than they are wet)

specialized plants that are adapted to live in wet soils with lots of groundwater

The many types of wetlands include marshes, swamps, bogs, meadows, mud flats, and other habitats where land and water meet.

In the not so distant past, up until even the 1970’s, wetlands were often considered to be wasted space. The marshy land at the edges of bays seemed wasted on the weedy plants that grew there and seemed like perfect, flat strips of land that could be filled in with soil and concrete to build desirable waterfront housing, office, and industrial space. In a span of 150 years, the San Francisco Bay watershed lost 90% of its wetlands. And only now are we realizing their worth and importance to a healthy ecosystem.

Wetlands serve many essential roles in the environment. They are critical habitat for many specialized plants and animals that survive nowhere else. The plants that live in a wetland act as a filter to soak up pollution that runs off upstream. In fact, several communities such as Arcata, CA and Phoenix, AZ use wetlands as part of their urban water treatment facilities instead of the harsh chemical treatments that must otherwise occur. Wetlands also serve as a reservoir to even out fluctuating water levels, soaking up excess water during a wet times and releasing stored water during dry times. Finally, as the nation learned in the Hurricane Katrina disaster, wetlands can serve as a buffer against natural disasters such as hurricanes (for more on this, see Katrina Case Study lesson).

2. Watersheds and Wetlands - Getting Ready

Getting Ready

Set out cardstock paper.

Fill water bottles (or kids can do this).

Collect the remaining materials needed for each group of 3 students (4 pieces of kitchen sponge, 1 water spray bottle, a multi-color assortment of water-based markers) into their plastic bin and set out near cardstock paper.

Open the packet of drink mix and set aside with the spoon in a place students won’t readily access (or they’ll try to eat it!).

2. Watersheds and Wetlands - Lesson Plan

Lesson PlanPart 1 – Building a watershed

Tell students to imagine that it is raining. Ask the students: “Where does raindrop go after it hits the school building? Where does it go from there? Where does it end up?” They should be able to trace it to a gutter. You may need to prompt them towards naming a nearby creek and onwards to a river, bay or ocean. You may want to draw a diagram of this path on the board.

Discuss the idea of a watershed. It includes all the land that water flows over and through to get to a larger body of water. Help students imagine what this means in terms of a raindrop that falls in different places in your watershed. Use a map if you want. It is not important that all the kids completely understand the idea right now. The activity that follows should help consolidate the idea for kids that aren’t getting it right away.

Tell the students that they will be building models of watersheds and observing what happens to their models when it “rains”. Briefly demonstrate what they will be doing to make their watershed (see steps 5-8 below) so they can see a nearly finished product before setting the kids loose.

Split the class into groups of 3 and have 1 member of each group collect 3 sheets of cardstock and 1 watershed tub. The rest of the group should clear everything off the tables except for a pencil for each student (they may get wet).

Crumple the sheet of cardstock into a ball then slowly flatten it out again. You should have a piece of paper with many valleys and ridges. Pick one end to be the top; this end will have tall mountains. The other end will be near a bay.

First, add water to your watershed – creeks that run into rivers, lakes, ponds. Make students think about where to put these rivers. Will they be at the tops of ridges or in the valleys? Where might lakes form?

Next add natural areas – animals, trees, plants, rocks, sandy banks. Add urban and agricultural areas – houses, cars, schools, farms, gardens, factories, roads, cars. Make students think about where to put various things. Where would you find forests? Where would you find meadows? Where would animals want to live? Where might it be very rocky? Where would people want to build houses? How would they get to their houses? Where would they work and go to school? Where would their food come from? Would you want to build a farm at the top of a mountain? Allow 5-10 minutes for students to finish their watersheds. They should be very colorful at this point.

Carefully fit the watershed into the plastic bin so that the mountainside is propped up on the narrow end of the bin (the mountain end) and the land slopes gradually towards the far end of the bin (the bay end), leaving a 2-3 inch gap between the end of the paper and the bay end. Wedge the paper snugly in place leaving as little gap as possible between the sides of the bin and the paper.

Take one of the markers and prop the mountain end of the bin up a little. This is to make sure that a bay forms on the bay end and does not run back under the land.

The 3 students should take turns spraying the paper using the fine mist setting. Spray for 3-5 minutes until there is a decent sized puddle in the bay end.

Give students the Watershed and Wetlands Questions handout and give students a few minutes to answer the first set of questions. The questions do not have to be used during class. You could use the questions to being a class discussion or use them as a homework assessment. I found that the discussions following each activity were more directed and targeted after students had thought about the activity individually first. I still collected the questions as an assessment.

When students have finished writing their answers, begin a discussion of how this model represents a watershed and how different things affect the watershed. If you still have the diagram of your watershed on the board, you could add these ideas to your diagram. Now is the time to really consolidate the idea of a watershed. Some questions you may want to consider include:

What path did the rain take through your watershed?

What effect do natural areas have on the watershed? Urban areas? Agricultural areas?

What is “runoff”? Is runoff different in natural versus urban versus agricultural areas? It is important to distinguish erosion from urban runoff. Also, it may be interesting to think about differences in urban versus agricultural runoff.

What affect does runoff have on the bay?

What is a watershed? How is this model similar to a real watershed? How is it different?

Part 2 – Adding Wetlands

Tell students that they will now build another watershed. This time, we will compare watersheds with wetlands to those without. Open a discussion of what students think wetlands are. Have they ever seen one? What does it look like? What kinds of plants and animals live there? If they don’t know the term wetland, they will likely have heard of a marsh and can bring up a good mental picture.

Pair teams up with one another. One team will have a wetland represented by sponges at the border between the land and the bay; the other will do the activity exactly as before (in the third rendition, they will switch roles so that everyone has a wetland once).

Clean up the materials and allow groups to create a new watershed with a new sheet of cardstock paper. It should not take as much time this time nor is it necessary for the watersheds to be as elaborate.

Set up the bins as before, however, one team should add a tightly packed row of damp sponges to the border between the land and the bay. THE SPONGES MUST BE DAMP. They should not be sopping wet, nor should they be wrung out as much as possible. They should be somewhere in between so that some water could still be wrung out if you tried.

Place the watershed with wetlands directly beside the watershed without wetlands and prop up the mountain end with a marker.

Allow it to rain an equal amount on each watershed. The students should make an effort to squirt the 2 watersheds an equal number of times. As it rains, encourage them to notice any differences between the 2 watersheds.Stop when a decent sized bay had built up – about 3 minutes.

Give students a few minutes to answer the second set of questions. When students have finished writing their answers, begin a discussion of what the role of watersheds might be. Some questions you may want to consider include:

Were there any differences in how quickly each bay filled? What does that mean about what wetlands do in times of heavy rain? Introduce the idea of wetlands as sponges during wet times and reservoirs during dry times to even out the flow of water.

What happened to the color of the bottoms of the sponges? What does this represent? Introduce the idea of wetlands as filters for pollution.

Part 3 – Toxic Waste!

Have students hypothesize what might happen to a watershed if a truck carrying pesticides crashed along a highway near a creek. What parts of the watershed might be affected?

Students will now have a chance to test their ideas on their models. As before, there will be one team with a wetland and one without, however they should switch roles. A spoonful of pesticide will be added to each watershed before it rains.

Clean up the materials and allow groups to create a new watershed with a new sheet of cardstock paper. Set up the bins as before, placing the watershed with wetlands directly beside the watershed without wetlands and prop up the mountain end with a marker.

At this point, the teacher should go around and add a teaspoonful of drink mix to the middle of each watershed.

Allow it to rain an equal amount on each watershed. Notice any differences between the 2 watersheds. Stop when a decent sized bay had built up – about 3 minutes.

Give students a few minutes to answer the final set of questions. When students have finished writing their answers, begin a discussion about the differences between non-point source pollution (runoff) and a pesticide spill. This activity should clearly illustrate how a single event in one location can affect a very large area and affects all downstream water users including wildlife in the marsh and the bay. Students will observe that while a wetland can soak up some pollution, some will also leak through into the bay. Can it be cleaned up once it gets into the water? Emphasize that although a waste spill is far more dramatic, urban non-point source pollution accounts for the vast majority of the pollution in most watersheds.

Given what we’ve discovered about watersheds and wetlands, what can we do to help them thrive? Have students brainstorm ideas.

Clean up.

2. Watersheds and Wetlands - Assessments

Assessment

The Watershed and Wetlands Questions can be used as an assessment tool.

Have students create a flyer that encourages other students to do something to help their watershed. Post them around the classroom or around school.

Go on a field trip to a wetland! Even better, do some restoration work there. For one idea, see the Save the Bay Field trip.

Delve into a case study of how wetlands form, how they are destroyed, and what the effects of wetland destruction are. Research your local area or investigate the wetlands of Louisiana and their role in the Hurricane Katrina disaster. See the Katrina Case Study lesson.

2. Watersheds and Wetlands - Sources and Standards

Sources The idea for this lesson came from the “Watershed in your hand” lesson from the Watershed Project’s Kids in Creeks curriculum and from the “Wetlands in a pan” lesson from Save the Bay’s Watershed curriculum. Save the Bay’s versions of these lessons are available below as pdf documents.

The following sites provide excellent scientific background information about wetlands and watersheds.

Although out of print, the USGS Water Resources Outreach Program has produced 9 fabulous posters with beautiful, colorful depictions of watersheds, wetlands, waste water treatment, water quality and more. Each poster has activities on the back with you can view online.

Standards Grade 6

2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept:

a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape.

b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns.

7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:

a. Develop a hypothesis.

f. Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map.

3. Katrina Case Study

Through a demonstration, students learn about the balance between subsidence and flooding in the formation of a wetland. Students then watch a short 15 minute PBS video about the wetlands ...

Summary Through a demonstration, students learn about the balance between subsidence and flooding in the formation of a wetland. Students then watch a short 15 minute PBS video about the wetlands of Louisiana. They will discover how levee building and the subsequent loss of wetlands contributed to the severity of Hurricane Katrina’s effect on the city of New Orleans. Finally, the class holds a discussion geared towards environmental stewardship and habitat restoration.

Objectives Can explain how subsidence and flooding contribute to the maintenance of wetlands. Can explain how levees prevent flooding and exacerbate subsidence. Can explain how wetlands protect shoreline from natural disasters such as hurricanes and flooding. Can discuss the goals of habitat restoration. Can recognize the importance of environmental stewardship.

3. Katrina Case Study - Logistics

Computer with internet access, preferably with a projector for the whole class to watch at once, although multiple computers that groups of 4 students can share will also work.

Watering can to simulate rain

Pitcher, watering can, or container you can pour muddy water from

Masking tape

Clear plastic tray or cup with 3-4 holes punched in the bottom (the clear lids of take-out salad containers are perfect although clear plastic cups will do as well.)

Square of cheesecloth large enough to cover the bottom of the tray or cup

Good loamy soil with a mix of sand, silt, clay and organic matter to represent marsh soil (garden soil is fine although you can always collect soil from a marsh to study and observe the real thing)

Hand trowel

Large basin that your tray can sit in (a large plastic dishwashing basin works well)

Setting classroom

3. Katrina Case Study - Background

Teacher Background The recent hurricane in Louisiana is an ideal opportunity to connect what students are learning about wetlands to real world situations. Students with some background knowledge of what wetlands are and the important environmental roles they play can now apply these concepts to events in the Mississippi River delta.

In their natural state, wetlands are caught in the balance between subsidence and flooding. Subsidence in the most general sense is the sinking of soil relative to sea level. Subsidence is a natural part of wetlands due to soil compaction – air pockets in the soil collapse under the weight of the soil above. In addition, some soil is eroded away by water and wind. Humans contribute to subsidence by extracting oil and natural gas (the soil above collapses when the oil below is removed). Although wetlands are sinking little by little, regular flooding brings in new sediment to rebuild the lost soil and maintain the soil levels in the wetlands. As the plant life in wetlands die, the decaying organic matter also contributes to the overall building of wetland soils. In its natural state, these two forces – soil loss through subsidence and soil building through flooding – are in balance, or in fact, wetlands grow over time as new sediment pours in from rivers and streams.

However, human developments strongly encourage the building of levees, dams, and canals to control flooding and improve water traffic. This prevents the soil building part of the equation, leaving an overall loss of soil year after year. The sediments in the canals shoot out to sea rather than rebuilding wetland soils. Wetlands shrink and eventually disappear. Land sinks. This is why much of New Orleans is below sea level. In fact, many other urbanized delta regions such as the Sacramento River Delta are experiencing the same subsidence problems.

Wetlands provide a natural sponge to soak up flood waters and act as a speed bump, slowing down hurricanes and blocking storm surges. Without much of the wetlands around Louisiana gone and with large areas of developed land below sea level due to subsidence, the effects of Hurricane Katrina were amplified upon the city of New Orleans.

So what can we do? First and foremost, we can educate ourselves and others about the science behind subsidence in order to understand the problem and not make the same mistakes in the future. Secondly, we can protect the few wetlands that remain as stewards of the environment. Finally, we can engage ourselves in rebuilding wetlands through habitat restoration efforts, many of which welcome teachers and their students to participate.

Student Prerequisites Students should be familiar with what wetlands are and the important functions they serve in an environment. It is helpful if they have played with soil and looked at the components in soil (see Soil Analysis lesson) although it is not essential.

3. Katrina Case Study - Getting Ready

Getting ReadyFor Subsidence Demonstration

Make 3-4 hole-punch sized holes in the bottom of the cup or tray.

Cut a square of cheesecloth to cover the holes.

Add a 4 inch layer of soil.

Put the tray inside the larger basin to catch any runoff. Water the soil until water just begins to drip out the holes in the bottom.

Use the hand trowel to fluff the soil slightly and then smooth the top surface so that it is mostly even.

Use a piece of masking tape to mark the top of the soil. Match the bottom edge of the tape to the top of the soil.

Fill the watering can about halfway with water.

In the pitcher or second watering can, create a mixture of soil and water - approximately 1 cup soil for 2 parts water. Stir.

Preview the video now or pause it to be ready to go when the kids arrive.

3. Katrina Case Study - Lesson Plan

Lesson PlanSubsidence Demonstration

Quickly review wetlands with the students. What are wetlands? Why are they important?

Next, tell students that you are going to show them a model of what happens to soil in wetlands over time. Bring out the tray with soil, the watering can and the pitcher of muddy water. Show the students what is in the tray. In particular, point out the level of the soil and the masking tape that marks the surface.

Explain to students that the soil in wetlands is a mixture of different sized sediments (clay, silt, sand), organic material, and water. In the soil there are air pockets. As soil gets exposed to rain, wind, and animals walking over it, it compacts. At this point, alternately use the hand trowel to pat down the soil in the tray and use the watering can of water to simulate rain. The level of the soil should subside up to an inch.

Ask the students what they notice. What happened to the level of the soil? Why? Ask students to help define compaction and subsidence given what they observed.

This process is always happening. Over time, the wetlands would sink completely underwater and disappear. Therefore, subsidence must be balanced by some other constructive force or the wetlands wouldn’t exist. Describe how rivers pick up sediments on their way down from the mountains in the watershed. Stir up the mud in the pitcher. These sediments are carried downstream by the water until they slow down as they pass through the wetlands. Pour some of the muddy water on the soil. Every so often, the river will flood, causing even more sediment to flow out onto the land. Mix up the pitcher thoroughly and pour a large quanity of the muddy water onto the wetlands, allowing a small layer of water to cover the surface and slowly drain out from the drain holes below.

Again, ask the students what they notice. What happened to the level of the soil? Why? Ensure that students see the balance between subsidence and sedimentation as natural events that contribute to a healthy wetland. Encourage students to predict what would happen if there was more sedimentation than subsidence or what would happen if flooding was prevented altogether.

Video

Tell students they will watch a video about Hurricane Katrina. If you have time, students may share some of the things they know about the disaster from the media.

Begin a discussion of the video focusing on why there are fewer wetlands and how that increased the severity of the damage caused by Katrina. Some questions you may want to consider include:

Before the Europeans came to Louisiana, was there more subsidence or more sedimentation? How do you know?

When New Orleans was first settled, was it above or below sea level?

Why did settlers build the levees? What effect did this have on the wetlands?

What else has been built by humans? What impact do these other structures have on the wetlands?

How much of the original wetlands remain? How quickly are wetlands being lost?

How do wetlands reduce the impact of hurricanes?

Allow the discussion of wetlands gradually transform into why wetlands are important and what we can do to save them. Some questions you may want to consider include:

Did people from the past not care about wetlands? (No, protecting their homes from flooding was more important to them and they didn’t know that wetlands were valuable.)

Should we care about wetlands loss? Why?

Do you think our politicians care about wetlands loss? Should they?

Do you think your parents know about wetlands loss? How can we teach them?

Should we protect the wetlands that are left? How should we do that?

Should we try to build new wetlands? Where?

What does it mean to be a steward of your environment?

End class on a positive note by brainstorming ways students can help protect, save or restore wetlands.

3. Katrina Case Study - Assessments

Assessment

Have students teach a family member about the connection between levee building, wetlands loss, and Hurricane Katrina. Have the family member write a short paragraph about what they learned from the student.

Ask students to locate a wetland in their local area and find out what plants and animals are there, if they can visit it, and if there are any on-going habitat restoration efforts there.

National Geographic ran an article in October 2004, 1 year before Katrina, discussing the loss of wetlands in Louisiana and the devastation that would be caused by a large hurricane. Have students read the article and make comparisons between the predictions and what actually happened a year later.

Going Further

NOVA and Frontline will air “Storm that Drowned a City” on November 22 at 8 pm. It promises to be an hour long investigation of the science behind Hurricane Katrina, going into far more detail than the 15 minute video highlighted here.

USGS has a great series of hands-on activities called the Fragile Fringe which provides extensive teacher information and resources on wetlands, their importance and their loss.

GET INVOLVED! The EPA has an Adopt Your Watershed campaign encouraging kids to become environmental stewards and join forces with the many groups leading cleanup and restoration efforts around the country. To adopt a creek and conduct habitat restoration activities here in the Bay Area, my students and I have worked with:

Standards Grade 6 2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept: a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape. b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns. d. Students know earthquakes, volcanic eruptions, landslides, and floods change human and wildlife habitats.

4. San Francisco Bay Watershed

Students get an introduction to the San Francisco Bay watershed by studying a map of California. The concept of a watershed is solidified using the San Francisco Bay watershed as ...

Summary

Students get an introduction to the San Francisco Bay watershed by studying a map of California. The concept of a watershed is solidified using the San Francisco Bay watershed as an example. Major geographical landmarks are identified on the map. Students then turn their hands into a portable map of the watershed. They discover how the water cycle determines the flows of water in different seasons, and therefore determines the utility of dams and reservoirs to even out the flow. In the process, students learn about the reasons the Bay is so important to California’s people, economy, and wildlife. This lesson may be extended into a history of the San Francisco Bay lesson.

Objectives Can feel a sense of place and connectedness to other parts of the state. Can identify the major landmarks in the San Francisco Bay watershed. Can see similarities between very large watersheds (on a statewide level) and very small ones (on a neighborhood level).

4. San Francisco Bay Watershed - Background

Teacher Background
The San Francisco Bay watershed covers 40% of the state of California. It provides drinking water for 2 out of 3 Californians and is the mainstay of the $18 billion dollar agricultural industry in this state. But it’s not just people who benefit. California is one of the biodiversity hotspots of the world, right alongside the Amazon River basin, Hawaii, and southeast Asia. There are large numbers of specialized habitats (like redwood forests) and endangered species who depend on the San Francisco Bay watershed for their survival. All Californians should know something about this critical aspect of their state.

Historically, the San Francisco Bay is relatively young. A million years ago (very recently in geologic time), a lake filled the Central Valley and drained out Monterey Bay. It was only 560,000 years ago that movement along the San Andreas Fault sealed off the passage through Monterey Bay and opened a new passage through San Francisco. Since then, due to the melting and refreezing of glaciers and ice sheets during the Ice Ages, at least 5 different San Francisco Bays have been known to exist. During an Ice Age, Earth’s water is primarily trapped in the mountains and polar regions as glaciers. The sea level drops up to 300 feet or more and beachfront property is miles offshore near the Farallon Islands. During inter-glacial periods, the glaciers melt, refill the oceans, and a Bay forms approximately where we find the Bay today.

My students had a very difficult time with the concept of the Ice Ages. Most held the mistaken belief that during the Ice Age, world temperatures plummeted suddenly (in a single lifetime or less) and the entire Bay was frozen as a gigantic skating rink. They believed the average temperatures on a typical October day to be around negative 20 degrees Fahrenheit. They knew there were animals but believed there were no plants that could possibly live in such cold temperatures. It took a lot of coaxing and evidence to convince them that this was not the case. In fact, the average temperatures during the Ice Ages were only 10-12 degrees less than they are now. While this does not sound like a big change, this is approximately equivalent to moving Canadian weather down to San Francisco.

The most recent cycle started 20,000 years ago during the middle of the last Ice Age. Ice Age animals such as bison, camels, ground sloth, mastodon, and saber tooth cats roamed the area surrounded by an assortment of Mediterranean plants. Around 10,000 years ago, the large animals began dying off, the Ice Age receded, and a small spike of ocean water entered what is now San Francisco Bay. 5,000 years ago, early Native Americans settled in the Bay Area. The Bay continued to grow by several inches per year. By 2,000 years ago, the Bay had filled to near its current size.

The Gold Rush has an enormous impact on the Bay. Hydraulic mining, a mining technique in which high pressure water hoses washed away entire hillsides to reveal the gold within, washed 12 billion tons of sediment down the rivers and into the Bay. Riverbeds became shallow and caused massive flooding in the Central Valley. The Bay itself became far more shallow and is now an average of only 14 feet deep. Transportation channels must be continually dredged to permit large boats to pass. Moreover, miners used the deadly toxin mercury to help extract gold. 12 million pounds of mercury washed downstream to mix with the sediments of the Bay.

California’s Sacramento River Delta is unusual in that it is an inverted river delta where two rivers converge and are forced through a single pass rather than a traditional river delta where a single diverges into many rivulets on its final journey to the ocean.

The soil is exceedingly rich in nutrients, which has made the delta region a rich agricultural area. However, levees built around the many delta islands have contributed towards extensive subsidence. Today, much of the delta lies below the waterline and is in danger of flooding if any of the levees should break.

The San Francisco Bay is not technically a bay. It is an estuary – a partially enclosed body of water where salt water and fresh water mix. While fresh water enters from the Delta, from rain, wastewater treatment plants, and groundwater, salt water rushes in with each tide through the Golden Gate.

The Bay itself has 4 lobes. The Delta feeds into Suisun Bay which then extends into San Pablo Bay. The Central Bay then opens out to the Pacific Ocean through the Golden Gate. The South Bay drains the areas surrounding San Jose and also exits via the Central Bay to the Pacific. In a satellite image, the Bay looks like a mermaid in profile. San Pablo Bay forms her head with Suisun Bay and the California Delta as her hair stretching towards the mountains. The Central Bay forms her body with her arms in prayer (“Please help save me!”) or others claim her arms reach out through the Golden Gate to the sea. The South Bay forms her tail.

4. San Francisco Bay Watershed - Getting Ready

4. San Francisco Bay Watershed - Lesson Plan

Have students look at the shaded relief map of California. Have a volunteer locate:

Their school

The tallest mountains, the Sierra Nevadas (Mount Whitney is the tallest mountain in the lower 48 states at 14,491 feet tall)

The San Francisco Bay

The state capital (Sacramento)

Los Angeles

The Pacific Ocean

Any other important landmarks they know from history and geography

Next lead the students through the watershed by following the journey of water through the seasons, similar to what they’ve already done in Water Cycle Stories. Focus on how water gets to the Bay and the differences in water flow through the seasons. The way I did this in my classes was a “Finish My Sentences” lecture. I walked students through the watershed, pausing and holding my hand out to invite students to fill in my silences at specific times. For instance I might begin, “Ok, we all know that water can’t run uphill, it only runs __(downhill)__. So water in California will start up high in the __(mountains)__ and make its way downhill towards the __(ocean)__. Look up here at the tops of the tall Sierra Nevada Mountains. Throughout the winter they become covered in __(snow)__. When spring comes, the snow __(melts)__, and the water runs through these __(valleys)__ as rivers.”

Next, have students decide whether or not a drop of rain that falls in a certain place will eventually find its way to the Bay (if it doesn’t evaporate first). Label those drops that make it to the Bay in one color and those that don’t make it in another color. For instance, have students raise their hand if the think a drop that falls in the Delta will end up in the Bay. Place a blue dot in the Delta since it will make it to the Bay. Next, ask them about a drop that falls in Los Angeles. Place a red dot there since it won’t make it to the Bay. Continue asking about various places around California until a pattern develops – any drops in or around the Central Valley will make it while any drops outside this area won’t.

Point out how students have just identified the San Francisco Bay Watershed. Review the definition of a watershed and highlight the borders of the watershed with your finger on the map. Stress the idea that the watershed is land, many of my students focused exclusively on the rivers and water features. If you choose to discuss the importance of the watershed to people, the economy, and wildlife, this is a good time to do so.

Show students how their hands can be turned into a model of the watershed that they can take with them wherever they go. Have students cup their hands together. Their hands should form a bowl with the pinkie-side of the palms touching and their fingers cupped outward and upward. This bowl represents the watershed. The tallest points, the fingertips, are the Sierra Nevada Mountains. The white ends of your fingernails are the snow-capped peaks. The left thumb represents the Siskiyou Mountains in the north. The right thumb represents the Tehachapi Mountains in the south. The heels your palms below your thumbs are the Coast Range Mountains. As the snow melts off your fingertips, the water runs along the valleys between your fingers as rivers. As they reach your palms, the Central Valley, they collect into 2 large rivers. The crease in your left hand is the Sacramento River while the crease in your left hand is the San Joaquin. The 2 rivers meet at the Delta and run out of the Central Valley down the place where your hands meet into the San Francisco Bay.

Ask the students whether this model can be used for other watersheds besides the San Francisco Bay watershed? Do all watersheds have high places? Do all watershed collect water into rivers? Explore the possibilities of using this model to represent your local watershed with its landmarks and special features.

4. San Francisco Bay Watershed - Assessments

Assessment

Have students label and color line drawing maps of California. Have them label the major landmarks (see vocabulary list) and shade in all the land that is part of the San Francisco Bay Watershed.

If your parents won’t go crazy with students writing on their hands, have pairs of students work together to label each other hand watershed models with a ball point pen.

Save the Bay has written an excellent map reading lesson, “Mapping your Watershed” that provides an excellent extension of the ideas covered here. Their mapping activity also leads into the From Maps to Models activity on MyScienceBox. You may download the lesson below. Teach students about the history of the Bay and make timelines to represent the major events and how they impacted the Bay.

Teach students about the history of the Bay and make timelines to represent the major events and how they impacted the Bay.

Visit the San Francisco Bay Model. The Army Corps of Engineers built a functioning hydraulic model of the San Francisco Bay that simulates the tides and currents. They have a marvelous visitor center and will give students a guided tour of the model.

Study the California Delta in more depth. There have been many hotly debated proposals on how to fix the delta in recent months, particularly since Hurricane Katrina. The California Department of Water Resources website provides detailed information about the Delta. The Sacramento River Watershed Program provides a listing of recent news articles concerning the state of the California Delta and the Sacramento River.

4. San Francisco Bay Watershed - Sources and Standards

SourcesIdeas
The idea for this activity came from the “Watershed in your Hands” Lesson from Save the Bay’s watershed curriculum (downloadable below). I have also seen Mike Moran, a naturalist at Black Diamond Mines, present this lesson at a teacher workshop in much the same way as I have described here – although his presentation is far better in my estimation.

MapsHubbard Scientific makes exceptional relief maps for most states. The California relief map is aroun $30 and is absolutely worth the cost. Students love the tactile quality of running their fingers across the mountains and much more readily grasp the idea of topographic maps in later lessons.

The USGS Store has the best deal on maps. For around $7-10 you get gorgeous relief maps and satellite images. The California State relief map is product #43555. The San Francisco Bay satellite image is #47251. You can find a map for virtually any US geographical area.

Blank line drawing California maps for students to color and label may be printed from Net State.

There are excellent free digital satellite images that may be downloaded and printed on the USGS website.

History of the San Francisco BayZpub.com has published an exceptional history of the San Francisco Bay.

And if these aren’t enough, go to the California Academy of Science San Francisco Bay resources list. They provide a huge list of books, videos, scientific papers, curriculum guides, and more all related to the San Francisco Bay.

Teacher Training Opportunities
I attended Save the Bay’s “Gold Rush to the Golden Gate” summer teacher training which was an extraordinary experience. We camped and canoed all along the watershed, experiencing the watershed first hand and drawing connections between the various parts of the watershed through speakers, activities, and discussions. GO! It’s amazing!

The Watershed Project offers wonderful training opportunities for teachers about the San Francisco Bay and its watershed.

Standards
Grade 6
Plate Tectonics and Earth’s Structure
Plate tectonics accounts for important features of Earth’s surface and major geologic events. As a basis for understanding this concept:
f. Students know how to explain major features of California geology (including mountains, faults, volcanoes) in terms of plate tectonics.

Shaping Earth’s Surface
Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept:
a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape.
b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns.
d. Students know earthquakes, volcanic eruptions, landslides, and floods change human and wildlife habitats.

5. From Maps to Models

Most middle school students have not seen or used topographic maps before. Conceptually, it is difficult for kids to see how a 2 dimensional topo map represents elevation. In this ...

Summary Most middle school students have not seen or used topographic maps before. Conceptually, it is difficult for kids to see how a 2 dimensional topo map represents elevation. In this activity, students learn how to create and read topo maps. By the end of the activity, they should be able to read a topo map and identify simple geographical features from a map. Teams of students mold a landform out of clay then place it into a clear plastic container. Water is added to the container in 1 cm intervals and students trace the “shoreline” of their model onto a transparency placed on the box lid. The resulting topo map is traded with another group who is then challenged to turn the 2 dimensional map back into a 3 dimensional landform. Several options are provided for creating the final model based on the materials available to the class. In fact, having more than one option of how to create the model often leads to greater understanding of how topo maps represent elevation.

Objectives Can understand the construction of topographic maps and the use of contour lines to show the Earth's surface in three dimensions. Can identify major geographical features on a topographic map. Can recognize what lines on a topographic map represent. Can create a topographic map from a 3 dimensional model. Can create a 3 dimensional model from a topographic map.

5. From Maps to Models - Logistics

Time135-150 minutes (approximately 3 class periods)

GroupingTeams of 2-4 students (I found this activity works best with groups of 3. Students stay engaged and can get access to the materials, but as a teacher, you don’t need to provide as many sets of materials as with groups of 2.)

MaterialsThe class needs

several example topographic maps for students to examine before they begin (see Sources section below)

1 flat, transparent lid for the plastic container (Most plastic storage containers come with textured, opaque lids. You need something like a sheet a clear Plexiglas that can sit over the top of the box and which students can write on. I recently discovered these plastic salad boxes at Smart and Final that provide a container and a lid in one!)

access to a pitcher of water with 4 drops blue food coloring (I had 2 teams share 1 pitcher)

1 plastic ruler

For making models from topographic maps each group needs

2 copies of a topographic map (1 original and 1 photocopy)

1-2 pairs of scissors

1 ruler

1 fine-tip Sharpie or overhead marking pen

one of the following:

7-8 clear, stacking salad tray tops (available at Smart and Final or other restaurant supply stores)

3-4 sheets cardstock paper and a lemon sized ball of clay

3-4 sheets of EVA foam

1 fist-sized lump of Plasticine clay

Settingclassroom

5. From Maps to Models - Background

Teacher Background Topographic maps are often very difficult for middle school students to understand. They are covered in squiggly lines and unfamiliar symbols and bear little resemblance to the road maps and political maps students may be more familiar with. The key is to use models to help students make sense of these maps.

What is a topographic map (or topo map)? These maps provide a way of showing a 3 dimensional landscape on a 2 dimensional surface. The most distinctive features of a topographic map are the contour lines. Each line represents an imaginary line that connects points that are the same elevation above sea level. Thus, if you walk along a contour line, you would not climb up or down, but stay at the same elevation at all times. USGS maps, the standard topographic map, draw contour lines in brown, labeled at intervals with numbers that represent the elevation above sea level or, in the case of bathymetric maps, the elevation below sea level. Other colors you might find on USGS topo maps are green for vegetation, blue for water features, red for major roads, and grey or black for human developments such as smaller roads, railroads and buildings.

Topo maps are used by most often for navigation so that hikers and explorers can get a sense of the terrain. They are also used by scientists to observe things based on their location and their elevation.

Contour lines are spaced at regular intervals (every 10 feet above sea level is marked with a different line for instance). Thus, the closer 2 lines are together, the steeper the area. Hills can be identified by concentric circles that grow smaller and smaller until you reach the peak of a hill. Depressions such as a dried out pond or the crater of a volcano are generally shown with hatched contour lines.

Student Prerequisites Familiarity with reading other types of maps – political maps, raised relief maps, road maps, etc. – is useful. I highly recommend Save the Bay’s “Mapping your Watershed” activity that can be downloaded at the bottom of the San Francisco Bay Watershed – Sources section.

Gather materials for making models from topo maps: 2 copies of a topo map, scissors, ruler, markers, and one (or more) of the following:

7-8 clear, stacking salad tray tops (available at Smart and Final or other restaurant supply stores)

3-4 sheets cardstock paper and a lemon sized ball of clay

3-4 sheets of EVA foam

1 fist-sized lump of Plasticine clay

You will want to try this activity yourself before you do it with the students. The model you make from the topo map can serve as an example for your students to emulate.

5. From Maps to Models - Lesson Plan

Lesson PlanIntroduction and Making Clay Models

Tell students that when we study watersheds it is useful to know how the land dips and rises – where the hills, valleys, ridges, stream beds, and plains are. Most maps don’t tell us this information. They may show cities, roads, and rivers, but not valleys, ridges, and mountains. Tell students that there is a special type of map called a topographic map that does show how the land rises and falls.

Give students copies of various topo maps. Ask them what they notice. Have them trace a contour line and tell them what a contour line is. Have them notice how some lines are labeled with the elevation. Have them look for hills by finding concentric circles. Have them look for steep places by finding lots of lines close together and look for flat places by finding lines spaced very far apart. If you have a raised relief map available, help students draw comparisons between the two and see a relationship between these two types of maps. Their understanding will be, and should be, very superficial at this point.

Tell students that over the next few days they will be making a model clay island, making a topo map of their island, giving their topo map to another group, and that other group will try to recreate their island using clay or other materials. Divide students into groups.

Give each student their first set of materials for making clay models and give them rules for their islands:

islands should fit on their transparency

islands should have high and low regions such as mountains and valleys

islands should not have extremely steep cliffs or overhangs

islands should not be too complicated

on the highest point of the island, place an “x” using the other color of clay

Give students 15-20 minutes to make their islands. Circulate among them making sure they are following the rules. Groups that finish early can add features such as a peninsula near the water, a stream coming down the mountainside, etc.

Making a Topo Map of the Model

Using one of your students’ clay models, demonstrate the procedure for making the topo map.

Use the marker to label North, South, East and West on the transparency below the clay model.

Label the compass points on the large sheet of transparency as well.

Place the clay model in the bottom of the plastic container.

Place the lid over the container with the transparency on top, oriented the same way (according to the compass points) as the clay model below.

Holding your head very still above the lid, trace the shoreline of the island onto the transparency using the marker. Also trace the cross at the top of the tallest hill. This cross will be a reference point to help figure out where to put your head.

Remove the lid. Holding a ruler inside the container near the base of the island, pour blue water into the container until the water is 1 cm deep. Notice how the water creates an imaginary line where the elevation above “sea level” is 1 cm all the way around.

Replace the lid and the transparency, making sure the transparency is oriented correctly. Match the first coastline and the cross to the island below.

Again, holding your head very still, trace the new shoreline of the island – where the water level touches the model. (You can probably end the demonstration here. Students should continue onto the next step.)

Repeat adding water and tracing new contour lines until the island is completely submerged.

Give students the second set of materials. My students needed 30-45 minutes to create their maps.

When all the students are finished, you can assess their understanding so far by placing all the models up at the front of the room and collecting all the maps. Place a map on the overhead projector and look at its features. See if students can tell which model it belongs to. Use features such as the number of hills, distinctive coastlines, valleys, etc. to help students identify which model goes with which map.

Making Models from a Topo Map

Make a photocopy of each map. The original map should be left as untouched as possible while the photocopy is a working copy that may be cut up if necessary.

Using one of the students’ topo maps, demonstrate how to make a model from a topo map. See the table below:

Salad Tray Tops

Cardstock Paper

Foam

Clay

1. Trim the photocopy of the map so that it just fits on the flat bottom of a tray. 2. Trace the outermost contour line onto the first tray. 3. Trace the next contour line onto a second tray and stack it on top of the first. 4. Continue tracing and stacking until all contour lines have been traced.

1. Make a bunch of balls of clay approximately 1 cm tall. 2. On the photocopy of the map, write an “N” on the inside of each contour line on the North side of the island. 3. Hold the photocopy tightly on top of a piece of cardstock. Cut both the photocopy and the cardstock together along the outermost contour line. Label the north side of the cardstock with an N. Set this piece aside. 4. Hold the now smaller photocopy onto a new section of the cardstock and cut out the next contour line and label the north side. Stack this new piece of cardstock on top of the first using some clay balls as spacers to raise it up off the first. 5. Continue cutting out pieces of cardstock and stacking them until all contour lines have been cut out.

1. On the photocopy of the map, write an “N” on the inside of each contour line on the North side of the island. 2. Hold the photocopy tightly on top of a piece of foam. Cut both the photocopy and the foam together along the outermost contour line. Label the north side of the foam with an N. Set this piece aside. 3. Hold the now smaller photocopy onto a new section of the foam and cut out the next contour line and label the north side. Stack this new piece of foam on top of the first, orienting the north sides the same way. 4. Continue cutting out pieces of foam and stacking them until all contour lines have been cut out.

1. Roll out a sheet of clay that is approximately 1 cm thick. Make the sheet as even as possible. 2. Place the photocopy on top of the clay sheet and trace the outermost contour line with a pencil. You should create a shadow of the pencil line on the clay below. 3. Use the pencil, a popsicle stick or fingers to cut the clay along the contour line. 4. Roll out a new clay sheet and trace the next contour line on it. Cut another “pancake” and stack it on top of the first. 5. Continue rolling out, cutting and stacking new clay sheets until all contour lines have been cut out.

Give each group the original and photocopy of a different group’s topo map as well as the other materials. If you want, have students use the maps to predict what the model will look like before they actually make the model. Allow students 30-45 minutes to create their models.

Once all the models have been completed, put the original model, the map, and the second model side by side. Were there any problems? How similar are the two models? How are they different? Why aren’t they exactly the same? Look at the models to discover how different features (hills, valleys, ridges, plateaus, etc.) appear on the maps.

If you have time, go back to the example topo maps that were shown at the very beginning of this lesson. See whether students are able to identify elevations, features, and identify trends on the maps now.

5. From Maps to Models - Assessments

Assessment

Give students a simplified topo map similar to the ones they made and ask them to predict what it would look like in 3 dimensions. Ask them to identify different features: the tallest hill, the steepest part, the flattest part, the elevation of various points, streams, etc.

Use a topo map in the real world to navigate. Go on a hike with the students and have them identify hills and valleys in the world and orient themselves on a map to figure out where they are and how to get from place to place.

5. From Maps to Models - Sources and Standards

SourcesActivity descriptions and ideas
I first learned how to make topo maps from Eric Muller of the Exploratorium’s Teacher Institute. I changed the method for making the topo map from the models but otherwise our activities are very similar. You can download his "To Topo Two" activity below or from his website with other stellar activities.

RAFT describes 2 different ways to create 3-D models. Both are downloadable below or you can access them, and lots of other fabulous idea sheets on the RAFT website. The first “3-D Viewing Topo Lids” uses clear, stacking, salad tray tops. The second, “Making Mountains” uses EVA foam.

If you are an NSTA member, Science Scope had a fabulous article in its October 2005 issue called “Making Sense of Topographic Maps”.

Topographic map information
The best place to learn more about topographic maps is the USGS. For more information about the symbols commonly found on topo maps, see the USGS map symbols page. For more information about how topo maps are created and what they are, see the USGS topo map information page.

MaterialsS&S Worldwide has the best deal on EVA foam at $15 for 78 sheets.

Standards
7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:
f. Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map.

6. Topo Tour

Once students understand the basics of how to read and create a topographic map (see From Maps to Models lesson), students will study and label a topographic map of their ...

Summary Once students understand the basics of how to read and create a topographic map (see From Maps to Models lesson), students will study and label a topographic map of their local watershed. They will identify the creek closest to their school and mark the boundaries of their watershed. In the process, they practice recognizing hills, ridges, valleys, stream beds and other geographical features on a topographic map. Finally, students take their maps and walk a part of their watershed, matching their maps to their real world surroundings. If a walk through your neighborhood is not possible, the lesson can be conducted without the watershed walk. The watershed walk portion of this lesson may be combined with the Sediment Study Project.

Objectives Can understand the construction of topographic maps and the use of contour lines to show the Earth's surface in three dimensions. Can identify major geographical features on a topographic map. Can recognize what lines on a topographic map represent. Can correlate real world topography to contour lines on a topographic map.

6. Topo Tour - Logistics

Time 30 minute to study maps in the classroom 45-55 minutes to walk the watershed

Grouping individual

Materials

One 7 and 1/2 minute (1:24,000) USGS topographic map of your local area (see Sources section)

A few simplified topo maps showing only 7-12 contour lines (select a few of your students’ topo maps of their clay islands in From Maps to Models or see the Sources section for websites that have simplified maps available)

6. Topo Tour - Background

It is important to show students why a topographic map is useful in the real world, and not just as a classroom exercise. Students tend to be familiar with reading regular road maps. It’s important to show students that when contour lines are overlaid on a regular map, information about the topographical landscape is revealed in the patterns among the swirls and squiggles of the contour lines.

The way I conduct my classes is first by showing my students a topo map of the neighborhood immediately surrounding the school then taking them on a walk that highlights the changes in local geography including a hill, a ridge, and a creek-carved valley. Each of these geographical features are important for geologists and other scientists to be able to recognize on a topo map. In my classes, the watershed walk was combined with the Sediment Study Project. Different classes went to different study sites along the creek (source, mid-stream, and mouth) to observe the flow of water and collect sediment samples. On our way there, we plotted a course that would take us by interesting geographical features that can be identified on the map. Before heading back, the students plotted a return route that minimized sudden elevation changes. The precise routes and features to visit will depend on your own local geography. Suggestions are included within the lesson plan below.

If a walk through your neighborhood is not possible, do the classroom portion only.

6. Topo Tour - Getting Ready

Getting Ready

Get a 7 and 1/2 minute USGS topo map for the neighborhood surrounding the school.

Walk, bike or drive the watershed yourself.

Identify interesting geographical features on the map. Look for hills, ridges, cliffs, valleys, stream beds, etc, anywhere you can observe distinctive topographic features with abrupt changes in elevation.

Visit these places to see if they can be observed from public areas (sidewalks, parks, parking lots, etc.) making notes as you go. Pick the 3 best places to visit on your walk.

Make a copy of the USGS topo map for each student. You don’t need to copy the entire map. Size the map to include your school, the nearest creek, and the geographical features you will be visiting on your watershed walk. Ideally, include the boundaries of your local watershed. For some watersheds, this may not be possible. In this case, make 2 copies of the map using the enlarge/reduce feature of the copier. On one, include the entire watershed. On the other, zoom in on your school and the areas you plan to walk.

Adapt the Topo Tour worksheet for your watershed. Currently, all references are to Glen Echo Creek in the 94611 zip code in Oakland, CA. You will want students to label a few major landmarks including your school, any local parks, perhaps a nearby grocery store and some major roads.

Make a copy of the Topo Tour worksheet for each student.

Make overhead copies of simplified topo maps to show students examples of the geographical features you want them to be able to identify. Use the maps your students created or see the Sources section below for other maps to use.

Collect other topo maps for comparison.

6. Topo Tour - Lesson Plan

Lesson PlanMapping your Watershed

Begin class by showing examples of student created maps. Have students point out geographical features such as hills, cliffs, flat meadows, stream beds, ridges, valleys, lakes, etc.

Next show students the large USGS topo maps. Ask for a volunteer to identify the map that has their school on it. Ask for a volunteer to point out a hill and describe in words how he or she recognized it. Ask another volunteer to point out a valley, a cliff, a ridge, etc.

Give students individual copies of their watershed topo maps and the Topo Tour worksheets. Students can follow the steps towards delineating their watershed on their own or you can do the steps together as a class.

Identify and color code major landmarks on the map. Label buildings in black, parks in green, major roads in red, and water features in blue.

Draw blue arrows along the creek sowing the direction that water flows.

Identify the elevation of several features. Write its elevation beside your label.

Identify 10-15 hills or ridges on the map. Draw a green “X” on top of each of these hills or ridges.

Imagine a drop of rain falls on each hilltop you just marked. Where will the raindrop go? If water from that hilltop could find its way into your local creek, draw a circle around the “X” on that hilltop. If water from that hilltop cannot find its way into your local creek, leave it blank. Remember, water will always run downhill. Help students recognize what is downhill and what is uphill.

Look at the circled “X”s. Starting at the circled “X” nearest the mouth of our creek, connect the dots between the X’s until you have drawn a “U” shape all the way around the creek.

Lightly shade the “U” shaped region in yellow. You have now mapped your watershed!

Watershed WalkTell students they will now be going on a walk to some of the more interesting geographical features near the school. There are several ways to lead this walk:

You can point out the places you are going on the map ahead of time. Ask students what type of landscape they might expect based on what is on the map. When you get to the sites, see if their predictions are correct.

Start walking! When you get to a site, have all the students stop and observe the surrounding landscape before consulting their maps. Have them study their maps to figure out where they are and how the feature they are looking at in the real world appears on their topo map.

For advanced students, you may have them use their maps to decide where to go and how. Challenge students to plan a walk that gradually climbs up to the top of a hill along a ridge or that flows a stream bed into the bottom of a valley. Use your own local geography to pick the challenge.

6. Topo Tour - Assessments

Assessment

Play Topo Bingo! The USGS has created a fun Bingo game using topographic maps. Download the instructions, map and game at their site.

A more traditional worksheet about topographic maps has also been created by the USGS. This worksheet asks students to find geographical features, read elevations, and use topo maps to plan where to put everything from walking paths to airports.

Going Further

Have students use the local topo maps to plan a bike route from their house to school and back, keeping in mind that bicycling up a hill is really difficult but biking down is really easy and fun.

6. Topo Tour - Sources and Standards

Sources The US Department of Agrictulture’s Natural Resources Conservation Service has a useful handout about reading topographic maps and how to delineate watersheds using a topographic map. The simplified drawings on these pages are great simplified topographic maps to use with students.

If you want to find a specific type of geographical feature to show students how this looks on a topo map, see the Rocky Mountain Resource Center. They have compiled example maps for hundreds of interesting features that may be shown to students.

Standards Grade 6 Shaping Earth’s Surface 2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept: a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape.

Investigation and Experimentation 7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will: f. Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map.

7. Erosion Patterns

This lesson is an extension of the GEMS guide“River Cutters” by the Lawrence Hall of Science (see note below). In the GEMS curriculum, students are introduced to erosion by modeling ...

Summary This lesson is an extension of the GEMS guide: “River Cutters” by the Lawrence Hall of Science (see note below). In the GEMS curriculum, students are introduced to erosion by modeling the formation of rivers in tubs of diatomaceous earth, a silt-like substance into which meandering river channels and deltas form. This lesson builds off of the River Cutters activities by using a combination of sediment types in the models. They observe how gravel and large particles of sand remain in place whereas silt is washed downstream in fast flowing river channels. In contrast, where the water velocity slows as it reaches the newly forming bay, a beautiful silt-covered delta forms. These observations lead students to the conclusion that fast moving water picks up the smaller sediment particles and eventually deposits them in places where the water slows. Students can then take this theory to test it out in real world conditions at a local creek in the Sediment Study Project, observing sediments and water velocity at different sites along a creek’s length. The concept of how sediments are deposited becomes a core feature of subsequent geology lessons and investigations in which the environmental conditions surrounding the formation of large particled conglomerates may be differentiated from small particled shales and siltstones.

Special Note: This lesson plan is written with the assumption that students have some experience using the river models in the GEMS guide “River Cutters”, written by Cary Sneider and Katharine Barrett and produced by the Lawrence Hall of Science. In this guide, students make observations of rivers carved in just silt (diatomaceous earth), sequencing events in time, noticing patterns, recording information, and acquiring the terminology necessary to describe common erosion patterns. My students completed the first 5 sessions of River Cutters although completing the first 3 lessons is sufficient. So as not to infringe upon the copyright of the GEMS unit, only the extension activity is described here.

Objectives Can describe the major types of sediment. Can identify common river features and erosion patterns such as a river’s source, channel, mouth, delta, etc. Can model sedimentary deposition patterns. Can explain how sediment size and current velocity affects deposition. Can make observations and record data in a science lab notebook. Can draw conclusions from data.

7. Erosion Patterns - Logistics

Time 15 minutes – Set stage for the experiment 20 minutes – Run single sediment and mixed sediment rivers side by side 15 minutes – Teams make individual conclusions and clean up 15-20 minutes the following class period – Combine all data and make summative conclusions

Grouping Teams of 3-4 students. Half the teams will set up tubs with a single sediment (diatomaceous earth). The other half will set up tubs with a mixture of sediments (diatomaceous earth, playground sand, and aquarium gravel).

1 straightened paper clip , approximately the same length as the stir stick and thin enough to be inserted into one of the 2 holes in the stir stick

1 plastic food service tub, approximately 20”x15”x7”

1 piece of wood (1”x2” stakes are cheap and easy to find although they do have splinters) or other prop to raise one end of the tub off the table

For the class to share:

20 lbs of diatomaceous earth (see Sources for more information)

10 lbs aquarium gravel

10 lbs playground sand

measuring cup

sponge

several pitchers of water

blue food coloring

paper towels (for clean up)

Setting classroom

7. Erosion Patterns - Background

Teacher Background Erosion is the process by which sediments are transported by wind, water, ice, or gravity. Often people mistake erosion for weathering, the process through which rocks are gradually chipped away by abrasion, water, and ice into sediments, a topic that is studied in greater detail in the Geology Box. On the other hand, erosion is the movement of these sediments from one place to another. Erosion is a very natural and essential natural process upon which many ecosystems depend including beaches, deltas and wetlands.

The central aspect of this activity is the observation of differences in sedimentation patterns based on the velocity of water movement. The central principle is as water moves faster, it can carry larger sediments and more of them. The smallest sediment particles (silt and clay) are picked up first, followed by sand then gravel. Thus, a rain-swollen river will carry a great deal of sediments of all sizes while a slow, meandering stream will carry very little and only of the smallest sizes. As the current velocity slows, sediments are deposited in reverse order, gravel is dropped first, then sand, then silt and clay.

In most watersheds, rivers begin in the high mountains with steep slopes, and thus, with fast running water. The smallest sediments are quickly borne away, leaving behind the gravel and larger rocks. As the slope of the landscape lessens in the foothills, the river slows and sandbars may accumulate along the curves and twists of the riverbed. Finally, as the slope becomes nearly flat, either upon reaching the valley floor or as it reaches a body of water such as a lake or bay, the current velocity is reduced to a crawl and even the smallest sediments are deposited, leading to silt-covered deltas and clay-like mud covering the bottom of lakes and bays.

All of these processes may be observed in the river models in which silt from the faster flowing river channels is picked up by the water and deposited when the water slows in the bay at the base of the model, eventually forming a delta. The sand and gravel in the upper regions of the model are gradually exposed. If your students do the silt only river models described in the GEMS guide “River Cutters” they will soon discover that the rivers formed in the mixed sediment rivers are slower to form, straighter and shallower, more similar to a young river, owing to the higher percentage of gravel and sand which are not as readily carried away by the water.

In my classes, I spend 1 class period introducing the activity, conducting the experiment, and allowing students time to make observations and draw individual conclusions. I spend the second class period in a group discussion, leading students towards a clear theory to explain their observations.

Student Prerequisites Students need hands-on experience with soil separation tests in order to see how the smallest particles of sediment stay suspended in agitated water longer than larger sediments (see the Soil Analysis lesson). Although this is used as a demonstration before beginning this lesson, students recognize the patterns and their implications best when they make the discovery themselves.

In addition, it is strongly recommended that students complete a minimum of the first 3, and preferably, the first 5 sessions in the GEMS guide so that students have experimented with time (how long a river has been running) and with slope before adding the variable of multiple sediments to the model.

7. Erosion Patterns - Getting Ready

Getting ReadySetting up the demonstration

Fill the jar 1/4 full with gravel, another 1/4 full with sand and another 1/4 full with diatomaceous earth. Mix well.

Add a pea sized amount of alum, about 1/2 a teaspoon.

Fill the rest of the jar with water, leaving just a little air space at the top.

Seal the jar tightly.

Preparing the tubs

In HALF the tubs, place 13 cups of diatomaceous earth. Diatomaceous earth may be irritating to the lungs if it is inhaled so pour diatomaceous earth slowly. (These are identical to those used in River Cutters. If you have already conducted experiments from River Cutters, leave half the tubs the way they are.)

In the other HALF of the tubs, add 10 cups of diatomaceous earth, 2 cups of playground sand, and 1 cup of aquarium gravel. Mix the sediments together thoroughly. (If you have already conducted experiments from River Cutters, you can adapt half the tubs to mixed sediment without needing to discard the whole thing. Remove 4 cups of the diatomaceous earth from the existing tubs. Add 2 cups of playground sand and 1 cup of aquarium gravel. Add 2 cups of water. Mix thoroughly then adjust the moisture level until you can cut a channel.)

In ALL tubs, add 12 cups of water. Mix thoroughly. It should begin to resemble that fascinating non-Newtonian fluid, cornstarch in water. In the mixed sediments tub, the gravel and sand will likely rise to the surface – that’s OK.

The consistency of the mixture is very important. Check to see if there is too much water by lifting one end of the tub. If the sediment slides down to the lower end of the tub, then it is too wet. Use the sponge to soak up some extra water. Check to see if here is too little water by slowly pouring some water onto the surface. If the water soaks in before it forms a rivulet, then it is too dry and needs more water. Ideally, the water should trickle across the surface and erode a gully as it flows downhill.

Preparing the dripper systems

Cut a shallow V shaped notch in each cup.

Insert a piece of paper clip wire into each stir stick.

Gently curve the stir stick into U shape resembling the Saint Louis Gateway Arch or the end of an egg.

In each pitcher, put 3 drops of blue food coloring then fill the rest of the pitcher with water.

Saint Louis Gateway Arch

Chicken Egg

Working the dripper systems

Fill the cup with water

Dunk the stirrer into the cup so that the entire straw fills with water (insert the straw middle first with the ends pointing upwards). You should see bubbles come out of the ends.

Carefully pick the straw out of the cup. I find that holding a finger over one end of the straw helps.

Quickly turn the straw over so that the ends point downward and simultaneously stick one end (the end with your finger over the tip) into the cup. Position the straw onto one of the notches.

Hopefully, the straw drips slowly and steadily, around 2 drops per second. If there is no water at all, try again. If the water flows too quickly, bend the straw straighter. If the water flows too slowly, bend the straw into a deeper U shape.

7. Erosion Patterns - Lesson Plan

Lesson PlanIntroducing the activity

Tell the students that they will be exploring erosion when there are multiple types of sediments, not just silt (diatomaceous earth) as in the River Cutter experiments. Ask the students “What do you know about erosion so far?” Review the idea that erosion is the movement of sediment from one place to another by water, wind, or other natural forces. Review the idea that erosion happens when sediments are carried in a river – the river’s load - and deposited elsewhere.

Show the students the soil separation demonstration jar. Point out the mixture of silt, sand and gravel within. Ask students to predict what will happen if you shake the jar then allow the contents to settle. Remind them of their own experiences with soil separation tests if they have done them before.

Shake the jar vigorously for 10 seconds.

Set the jar down on a countertop. Have students make observations of what they see and notice. The gravel should settle to the bottom, sand in the middle and silt on the top.

Now ask students WHY they think the sediments layered themselves in this way. In particular, emphasize the idea that the tiny particles of silt stay suspended in water longer while the largest particles of gravel are densest and quickly settle to the bottom.

Explain the set up for today’s experiment: students will cut two rivers, one in a tub of just silt and one in a tub of mixed sediments like those in the jar. Ask students to predict what they think will happen. Some more specific questions to consider include:

What differences do you think there will be between the single sediment river and the mixed sediment river? (If students completed session 4 or 5 of River Cutters, remind them of some of the differences they observed: the depth of the channel, the width of the channel, the amount of material moved, how much it meanders, the number of tributaries, the size of the delta, etc. Ask them how they think each of these variables might play out in this experiment and why.)

What do you think will happen to the silt in the mixed sediment river?

What do you think will happen to the gravel in the mixed sediment river?

What do you think will happen to the sand in the mixed sediment river?

Have students write down their own hypothesis in their lab notebook. Make sure they explain why they think their results will turn out they way they predict.

Explain that students will be running a single sediment and a mixed sediment river side by side. The two rivers will run for 5 minutes, students will make observations, then the rivers can be run for 5 minutes more before a final set of observations are made.

Conducting the experiment

Divide the students into groups of 3 or 4. Assign each group to a condition, either single sediment or mixed sediment. Two groups should work at each table or cluster of desks so that a single sediment tub and a mixed sediment tub may be run side by side. Place the tub on the table, prop up one end with the wood, and place the dripper system inside at the top of he slope.

Have one student from each group gather the necessary materials: the appropriate tub, a piece of wood top prop up one end of the tub, a dripper system.

Distribute the pitchers of water around the room, ideally, one pitcher per pair of tubs.

Have students run five minute rivers in their tubs, starting the two rivers at the same time and adjusting the flow rates to be approximately equal. Circulate around the room to make sure everyone understands the directions and teams are working well together. Assist students as needed.

After five minutes, make sure that students have stopped the flow of the rivers. Check to see that students are making observations of their rivers in their lab notebook – drawing maps of the two rivers, labeling features, and writing 1-2 sentences describing their observations.

Have students run their rivers for 5 minutes more, again staring the rivers at the same time and adjusting the flow rates to be approximately equal. Circulate and help students as needed.

After the second five minutes has passed, make sure that students are making their second set of observations.

Finally, pose the following questions to the class:

What differences do you observe between the single sediment river and the mixed sediment river?

What do you think will happen to the silt in the mixed sediment river?

What happened to the gravel in the mixed sediment river?

What happened to the sand in the mixed sediment river?

Have students discuss these questions within their teams. When they feel like they have reached consensus, they should write down their conclusions in their notebooks.

When teams have finished their own conclusions, they may visit other teams’ rivers and compare them to their own.

If you are ending here for the day, have students put the materials back and wipe down their tables.

Group discussion (This discussion may take place the same day if you have time or the following day.)

Have one member of each team report their conclusions to the class. Create a list of conclusions on the front board or on an overhead. Note any conclusions reported by multiple groups and note any discrepancies, but do not discuss them until all groups have reported.

Students will probably observe that mixed sediment rivers are shallower, straighter, and wider. The gravel and sand should be exposed near the source and in the river channel while the silt accumulates in the delta and bay. Encourage a discussion as to why this might be.

Return to the class’ observations of the soil separation test and begin to put the pieces together. Some questions you may want to consider using to shape the discussion are:

Do silt particles behave differently in fast moving water (either the river channel or the sediment jar) than gravel particles? How? Why?

Where is the water moving fastest in their rivers and where is it moving slowest?

How does the speed of the current affect the sediment load, in particular, the types of sediment that might be suspended?

How does the speed of the current affect deposition, in particular, when different types of sediment might be deposited?

How do these models compare to real rivers in the real world? Would real rivers be more like the single sediment rivers or the mixed sediment rivers?

7. Erosion Patterns - Assessments

Assessment

Have students, either individually or in teams, propose a theory in answer to the questions: “How does the speed of the current affect the type of sediments that are carried and deposited by a river? When water moves quickly, what happens? When water moves slowly, what happens? Why?”

Going Further

Bring the conclusions of this experiment into the real world. How are different sediments distributed at a real creek? What causes the variance? See the Sediment Study Project for a detailed description.

7. Erosion Patterns - Sources and Standards

Sources
The primary inspiration for this unit is the GEMS guide “River Cutters”, written by Cary I. Sneider and Katharine Barrett and produced by the Lawrence Hall of Science. I strongly recommend this guide, even if you don’t intend to use it because they offer fabulous tips and recommendations for using river cutter tubs with students. In addition, the guide provides fabulous diagrams, handouts, homework assignments, suggestions, resources and more that can be used as a prelude or complement to this activity.

Georgia Perimeter College has some excellent notes on erosion written for their teacher education program by Dr. Pamela Gore.

Watersheds.org also provides a good overview about erosion, divided into Field and Slope Erosion versus Valley and Stream Erosion. Their website is useful for connecting common erosion patterns to a real world creek, Bryant Creek.

Standards
Grade 6
Shaping Earth’s Surface
2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept:
Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape.
Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns.
Students know beaches are dynamic systems in which the sand is supplied by rivers and moved along the coast by the action of waves.

All grades
Investigation and Experimentation
7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.

Project - Sediment Study

In this culminating project, students go out into the field and test their theories about erosion and sedimentation at a local creek. How are sediments distributed along the creek? Does ...

Summary In this culminating project, students go out into the field and test their theories about erosion and sedimentation at a local creek. How are sediments distributed along the creek? Does it vary by location (the source, mid-stream, and the mouth)? Does it vary by the velocity of the current? Different classes can collect information for the different study areas. At a study site, they will draw maps, measure the velocity of the current, and collect sediment samples from the creek bed. These samples are analysed back in the classroom for the percent of different sediments they contain. Finally, students stand back and examine their data to try to make sense of the sediments they find. If it is not possible to bring students to a creek, there are many ways to bring the data to them. Collect the sediment samples yourself with photos and water velocity information OR use the Suspended Sediment Database to draw your conclusions. This USGS database provides stream flow and sediment information for over 1,500 rivers and creeks nationwide (see the Going Further section for more information on using the USGS’s database).

Students collecting data at the creek.

Objectives

Can describe the major types of sediment. Can explain how sediment size and current velocity affects deposition. Can create a hypothesis and make predictions of what to expect from experimental data based on prior knowledge. Can make observations and record data in a science lab notebook. Can use their own observations and data draw logical conclusions.

Sediment Study - Logistics

Time Day 1: Experimentation (may be split into two days) 20 min describe the question and experiment and have students make hypotheses and predictions 5 min describe experiment procedures 30-45 min conduct experiment and collect sediment samples at the study site travel time to the study site and back will vary

MaterialsFor sediment study, each group of students needs: (I assembled all the materials into several shoebox-sized plastic containers to become our class set of “creek kits”. Many of these items are the same as those needed for the Habitat Survey lesson.)

Topographic map of the creek they will be studying, assuming you will be studying sediments at the creek in the school’s watershed, you should have a copy of this map from the Topo Tour lesson

first aid kit

extra film canisters

extra copies of the Sediment Study directions

field guides of local plants and insects

optional: water and paper cups

For classroom tests and interpretation each group needs:

1 copy of the Data Summary Sheet

3 clear 15 ml tubes with lids, glass or plastic

For classroom tests and interpretation the whole class can share:

2 tablespoons

2 rulers

1 small jar alum (available at supermarkets for pickling)

1 package removable dot labels or rolls of masking tape

several Sharpie markers

Setting Day 1 – Creek. Pick 3 study sites at different places along the creek. Make sure that the sediment makeup at each of the 3 sites is very distinct. I chose a pond at the source of our creek with mucky clay and silt above a layer of sand, a fast flowing area midstream with weathered river rocks and gravel, and a wide man-made channel near the mouth with a mixture of sediments.

Day 2-4 – Classroom.

Sediment Study - Background

In this project, I wanted students to grapple with the notion that science is rarely as simple as the textbooks. Usually, in a river, stream or creek bed, a fast-flowing midstream section will have lots of gravel and larger rocks and the mouth will have lots of silt and clay as the current slows. Usually, the riverbed at source will have whatever type of soil the surrounding hillsides are made of. However, in real life, things are rarely so simple. There are culverts that direct creeks underground, man-made concrete channels, and dams. There are polluters, dogs and gardeners to contend with, all of whom affect the types of sediments one will find in any given spot in an urban creek.

The beauty of this project is that the ability of fast-moving water to carry more sediment of larger sizes is so robust that irrespective of the other variations, if there is sediment at all to be observed, it will almost certainly follow this trend. Most importantly, students are able to look for patterns in real world data and consolidating everything they have learned about watersheds and erosion. Surprises come from changing students’ expectations of what a creek looks like at different places and from discovering the variability of data, even at a single study site.

In this project, different classes of students go to one of 3 sediment study sites to collect information. Students lay out a 4 meter transect line to create 5 imaginary lines stretching across the creek. Students do the following:

Draw a careful map of their study area

Measure the current velocity in meters/second

Approximate the width of the creek

Measure the depth of the creek 30 cm (approximately 1 foot) from the shore at each of their 5 imaginary lines

Collect a sediment sample from each of their 5 imaginary lines approximately 30 cm out from shore

Copy Data Summary Sheets for students to summarize their data and post for everyone to view.

On a bulletin board, wall, or at the top of the front whiteboard/chalkboard, create 3 areas for students to post their Data Summary Sheets.

Sediment Study - Lesson Plan

Lesson PlanDay 1: Experimentation

Before leaving the classroom, introduce the project by posing the following questions to students:

How are sediments distributed along a river or creek?

Does it vary by location (the source, mid-stream, and the mouth)?

Does it vary by the velocity of the current?

What other factors might affect the distribution of sediments and why?

On the front board, create a list of factors that students believe would affect the distribution of sediments.

Tell students that they will be analyzing sediment samples from different parts of the creek in the school’s watershed. They will be making observations of the sediments at different places along the creek and will be looking for the reasons that sediments have been deposited in those ways.

Point out the 3 sediment study sites on the topographic map of the creek. Assuming you will be studying the creek in the school’s watershed, students should already be very familiar with this map from the Topo Tour lesson. Ask students to point out the geographical differences between the 3 sites. Which site is at the highest elevation? Which site is steepest? Is any in a valley, on a flat plain, on a hillside, etc?

Have students open their lab notebooks and set up a new page with the title of the study, the date, etc. Have students write down the question: “How are sediments distributed along the creek in our watershed? If the sediments are different from place to place, what causes the variability?”

Have students make hypotheses about what to expect. I find that if you give students fill-in-the-blank style statements, I get much better hypotheses than if they are just told to make some predictions about what they might expect at each of the study sites and explain why. I used the following fill-in-the-blank style statements:

I think ______ are the most important factors that influence the way sediments are distributed along a creek.

At the first study site near the source I would expect to find _______, because ______.

At the second study site mid-stream I would expect to find _______, because ______.

At the third study site near the mouth I would expect to find _______, because ______.

If you are dividing Day 1 into 2 class periods, stop here and continue the following day with Step 7.

When students finish writing down their hypotheses, distribute the Sediment Study Directions and describe the experiment procedures that will be completed at the creek. Tell students what teams they will be working with and how to find a study site (you can assign them there or they may find their own site). Show them how to stake out their survey site with the string and stakes.

Depart for the trip.

When you arrive, make sure that each team has an appropriate survey site and a creek kit. Make sure that groups are setting up their string and stakes correctly.

Allow students to get started immediately collecting the information in their lab notebooks. Circulate among groups to help students who have questions.

Teams that finish early can sit quietly with a field guide and try to identify the plants and animals they found.

When all groups are finished, return to the classroom.

Day 2: Soil Separation Tests

Tell students to get out their soil samples. Tell them to set up a soil separation test with the sediment collected at their site, making sure to label each container with their team name, the sample number, and the location where it was collected.

Day 3: Data Analysis and Summary

Allow students 10-15 minutes to interpret soil separation tests and clean up those stations. For each sample, they should draw a picture of the separation test in their lab notebook, labeling each layer with what the layer is made of (gravel, sand, silt or organic material) and the height of that layer in millimeters.

Have students create a table like the one below in their lab notebook:

Line 1

Line 2

Line 3

Line 4

Line 5

Average

Percent

Silt/clay

Sand

Gravel

Organic material

Show students how to use this table to average the results from their 5 sediment samples and then turn the average heights into a percent.

This information, along with the other data can be entered on the Data Summary Sheets and posted below one of the 3 site headings around the room.

Day 4: Drawing Conclusions

Remind students of the questions posed at the beginning of this activity. Allow them to spend a moment rereading the hypotheses they made at the beginning of the project.

The remainder of this class period will vary according to the data your students collected and the conclusions that may be drawn from this data. The general idea is to have the students devise a way to summarize the data collected at each of the study sites and then look for patterns. I spent 20-30 minutes simply creating tables and charts with my students – tables of width and depth measurements, tables of current speed, tables of sediment composition, bar graphs for the more interesting types of data. I found that starting by comparing the width and depth measurements enabled students to imagine what each of the areas looked like – a pond, a small stream, a wide channel. Adding the current velocity information confirmed their suspicions of how quickly the water moved at each site. Finally, once they have had experience averaging the previous data, the most complicated task of interpreting the sediment composition data is more accessible than if we had tackled that first, even though that is the whole point of the exercise. Some issues that are interesting to explore:

Was there variability within the 5 sediment samples collected by a single team? Why is it important to collect 5 samples instead of just 1?

Was there variability among the data collected by the different teams at a single study site along the creek? What might have caused those differences?

What patterns in sediment distribution were found at each of the 3 study sites?

What factors (width, depth, current velocity, others) may have caused the variation in sediment distribution? Why do you feel this factor is important?

Sediment Study - Going Further

Going Further

The USGS has compiled a Suspended Sediment Database describing the distribution of suspended sediments across the United States. The database has answers to the questions for over 1,500 rivers and creeks across the United States: How much water is flowing in my river? How much sediment is suspended in the water? How much of this sediment is discharged and where? Information is collected daily over a period of years so your students can graph and plot data correlating stream flow to sediment load and deposition. The data is pretty daunting (pages and pages of numbers with complicated units of measure such as “daily mean suspended-sediment concentration in milligrams per liter”) so for use with students, it is best to cull the data down to a much smaller subset. For instance, if you wish to draw attention to yearly cycles in water flow, pick one day a month over 2 years. Have the students graph that information then look for patterns.

Did the Suspended Sediment Database not have everything you are looking for? Try the NWIS Database instead. This mind-boggling resource provides information about the amount of water, the water quality, water distribution, and the movement of both surface and underground water at 1.5 million monitoring sites across the country. Again, you can select a subset of this data for students to draw conclusions from.

Sediment Study - Standards

Standards Grade 6 Shaping Earth’s Surface 2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept: a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape. b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns. c. Students know beaches are dynamic systems in which the sand is supplied by rivers and moved along the coast by the action of waves.

All grades Investigation and Experimentation 7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.

Sub Plan - Bay Classroom Webquest

Students go on a web-quest for information on Save the Bay’s Bay Classroom website. They discover facts and information about the part of the San Francisco Bay, its history, the ...

Summary Students go on a web-quest for information on Save the Bay’s Bay Classroom website. They discover facts and information about the part of the San Francisco Bay, its history, the creatures that call it home, and ways they can help protect the bay. This easy activity requires little supervision and is thus offered as a great substitute teacher lesson plan or for one of those teaching days when you need a last minute lesson. Suggestions for making this lesson more interactive are provided.

Objectives Can identify the major events that contributed to the current state of the San Francisco Bay. Can describe some of the plants and animals that live in the Bay. Can explain the importance of the San Francisco Bay and its watershed to the state of California. Can describe some things students can do to help protect and preserve the Bay.

Bay Classroom - Background

Student Prerequisites None, although familiarity with the San Francisco Bay watershed is helpful.

Bay Classroom - Getting Ready

Getting Ready

Make copies of the Bay Classroom Web-quest handout.

Bay Classroom - Lesson Plan

Lesson PlanOption 1 – Individual Web-quest

Give students the student handout and allow them time to preview the questions they need to find answers to on the web.

Direct students to the Bay Classroom website. It is easiest for students to type in www.savesfbay.org then click the green “Bay Classroom” button to access the site.

Give students 40-50 minutes to read through the various pages of the website and answer the questions.

Collect the handouts when students are done.

If students finish early, invite them to try the Bay Quiz link from Save the Bay’s home page.

Option 2 – Expert in an Area Web-quest

Assign students to one of 4 groups: Bay History, Bay Basics, Bay Nature, or Bay Problems. Students are only required to find the correct answers to their assigned topic on the website, although the whole worksheet must be completed by the end of the period.

Give students the student handout and allow them time to preview the questions they need to find answers to.

Direct students to the Bay Classroom website. It is easiest for students to type in www.savesfbay.org then click the green “Bay Classroom” button to access the site.

Give students 15-20 minutes to read through the various pages of the website and answer the questions. If students finish their section early, have them move onto other sections.

Bring the class back together and have students that had the same topic sit together. Give them 2-5 minutes to quickly compare answers to the questions in their specialty and come up with a list of other facts they learned while researching their section.

Each group should pick a speaker and report the answers they found and the facts they learned to the rest of the class. Students in other groups should follow along and fill in their own worksheet as they go.

Bay Classroom - Assessments

Assessment

Collect the student worksheets.

Have students write a quiz based on what they learned from the webquest. The following day, they can trade quizzes and grade each other.

Bay Classroom - Sources and Standards

Standards Grade 6 Plate Tectonics and Earth’s Structure 1. Plate tectonics accounts for important features of Earth’s surface and major geologic events. As a basis for understanding this concept: f. Students know how to explain major features of California geology (including mountains, faults, volcanoes) in terms of plate tectonics.

Shaping Earth’s Surface 2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept: a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape. b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns. d. Students know earthquakes, volcanic eruptions, landslides, and floods change human and wildlife habitats.

Ecology (Life Sciences) 5. Organisms in ecosystems exchange energy and nutrients among themselves and with the environment. As a basis for understanding this concept: e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition.

Field Trip - Bay Model

This section will give you information to help you plan a field trip to the San Francisco Bay Model. The Bay Model is a working three-dimensional model of the San ...

Summary This section will give you information to help you plan a field trip to the San Francisco Bay Model. The Bay Model is a working three-dimensional model of the San Francisco Bay and Delta areas. It fills 3 warehouse sized buildings and students who visit get a guided tour, observing the flow of the water, learning about how scientists use scale models, and leaving with the impression that the Bay is a very big place.

Park ranger at the Bay Model.

Objectives Can develop a sense of scale from maps to the Bay Model to the real world. Can understand how scientists use scale models in scientific investigations. Can explain how tides affect currents. Can understand how the San Francisco Bay formed.

Bay Model - Planning Guide

Planning Guide According to the Bay Model Visitor Center: “The Bay Model is a three-dimensional hydraulic model of San Francisco Bay and Delta areas capable of simulating tides and currents. The Model is over 1.5 acres in size and represents an area from the Pacific Ocean to Sacramento and Stockton, including: the San Francisco, San Pablo and Suisun Bays and a portion of the Sacramento - San Joaquin Delta.”

According to my kids: “It’s HUGE!” “Wow.” “Check out how shallow the Bay is!”

You need to make a reservation for groups. With your reservation, students are taken on a ranger-guided tour of the facility. I asked my students to fill out a handout as they visited the museum. You can adapt the handout to suit your need by downloading it below.

Time at the Bay model passes quickly. 1 minute = 1 hour and 40 minutes in the real world. Thus, you can see the tides going in and out and watch the currents flow through the Golden Gate.

Field Trip - Save the Bay

This section will give you information to help you plan a field trip with Save the Bay. I brought 32 students to Arrowhead Marsh, a hidden wetland near the Oakland ...

Summary This section will give you information to help you plan a field trip with Save the Bay. I brought 32 students to Arrowhead Marsh, a hidden wetland near the Oakland Airport, to meet up with extraordinary Save the Bay Instructors. The day was divided into two parts: 1) Canoeing – where we did water quality monitoring, explored the marsh with all our senses, and went on a wildlife scavenger hunt 2) Restoration – where we repotted 300 native plants, cleaned up the shoreline, and went for a walk on a boardwalk above the marsh. Students were able to explore a wetland up close and observe a leopard shark, feel the Bay’s muddy bottom, and listen to the endangered snowy plover.

Objectives Can apply knowledge about water quality monitoring and the role of wetlands to the San Francisco Bay. Can conduct a scientific investigation. Can use a field guide to identify animals in the wild. Can participate in habitat restoration efforts. HAVE FUN!

Save the Bay - Planning Guide

Planning Guide Save the Bay has excellent educational staff that is very skilled at working with students. They offer canoeing programs (Canoes in Sloughs) and restoration opportunities at several sites around the Bay. You can also adopt a site and return to the same restoration site several times in a given year to assist in the transformation of a piece of wetland over time. They will even come to your classroom to do a pre-trip lesson if you wish. Given the quality of the restoration work that Save the Bay does, I strongly recommend a double program that combines canoeing and restoration work. The only drawback is that you will have less time on the water, but still enough for kids to learn and play.

The cost for programs is on a sliding scale depending on the number of students that qualify for free and reduced lunch. My students paid $30 each to attend which was well worth it.

To schedule a program, fill in the registration form available on the Save the Bay website or download it below. For more information, contact Save the Bay directly at: